Tool for opening holes in can containers



Oct. 27, 1964 KAZUO TANUMA 3,153,851

TOOL FOR OPENING HOLES IN CAN CONTAINERS Filed Aug. 20, 1962 United States Patent 3,153,851 FOR GPENENG HOLES IN CAN EQNTAENEES Kazuo Tanunia, 236 Koya-cho, Adachi-lsu, Tokyo-to, Eapan Filed Aug. 29, 19-52, Ser. No. 217,917 1 lClairn. (Cl. 30-16) This invention relates to can openers of the type which punctures and forms a hole on one surface of a can container containing a fluid by the forceful penetration of a cutting blade tip, the said penetration being accomplished by lever action.

Prior hole opening tools of this type have had the disadvantage, when opening holes in can containers containing a liquid under pressure, such as beer, of forming the said holes in such a manner that a portion of the said liquid is unavoidably permitted to be violently ejected out with the initially escaping gas, thereby causing not only waste of the liquid but also soiling of the objects near the container and unpleasantness to persons in the vicinity.

It is an object of this invention to provide a new and improved tool for opening holes in can containers in which the above-described disadvantage has been eliminated by a novel construction of the working end thereof.

The nature and details of the invention will be more clearly apparent by reference to the following description of one representative embodiment of the invention when taken in conjunction with the accompanying drawing in which like parts are designated by like reference numerals, and in which:

FIGURE 1 is a side elevational view of the embodiment;

FIGURE 2 is a plan view showing the lower surface of the embodiment of FIGURE 1; and

FIGURE 3 is an elevational view, in section taken along the line III-III of FIGURE 2.

Referring to the drawing, the tool of the invention comprises a handle part 1, claws 2 provided on the lower forward end thereof, and a working head, including a cutting tip 3, of novel construction which is the significant and essential substance of the present invention, and which will now be described in detail.

The working head of the tool is bent downwardly at a certain angle with respect to the handle part 1 as in conventional tools of this type.

One novel feature of the construction is that a groove 4 is provided in the lower or inner surface of the working head beginning at or very near the extreme end of the cutting tip 3 and extending rearward along the centerline of the tool.

As in the case of the conventional tool of this type and as shown in FIG. 3, the tool of this invention is used by positioning it on a can container 5 so that its claws 2 catch against the lower part of the rim head 6 of the container 5 and its cutting tip 3 rests on the top cap 7 of the container 5. Then when the handle part 1 is lifted so as to rotate the tool as a lever with the contact Patented Get. 27, 1964 ice between the claws 2 and the rim bead 6 as a fulcrum, the cutting tip is forced to puncture the cap 7 and form a hole.

When the container 5 is containing a liquid and a small quantity of a gas under pressure, the aforesaid groove 4, upon communicating with the interior of the container 5, permits only the said gas to escape first, thereby releasing the pressure within the container and removing the cause of violent ejection of the liquid.

In the case of a conventional tool of this type, the cutting action of the cutting tip is such as to tear a hole expanding toward the rim of the container top and to leave a triangular hole in the wake of the cutting tip. The sudden formation of this triangular hole permits the sudden release of gas and liquid. It is another novel feature of the present invention that the configuration and the angle of juxtaposition of the cutting tip 3, particularly its extreme end portion, with respect to the tips of the claws 2 are so designed that, during the initial phase of the puncturing action, the cutting tip 3 is caused to penetrate into the container top 7 in a direction substantially perpendicular thereto and to function, because of its tapered configuration, as a stopper or closing valve for the hole it is making. Accordingly, the hole is made substantially without escape of gas (not to mention liquid) until only the gas is permitted to escape as aforedescribed through the groove 4.

Although this invention has been described with respect to a particular embodiment thereof, it is not to be so limited as changes and modifications may be made therein which are within the full intended scope of the invention, as defined by the appended claim.

\Vhat is claimed is:

In a can opener of the type consisting of a lever-shaped handle, claws provided on the lower part and near the forward end of said handle to engage the head of a can to be opened, and a downwardly bent working head including a cutting tip presenting a lower, inner surface toward said claws, said cutting tip having a sharp point to pierce a can, the improvement comprising that said cutting tip is provided with a groove open to and formed in said lower, inner surface thereof extending to a point closely adjacent said sharp point, the lower inner side of said cutting tip, at the extreme end portion of said cutting tip forrning said sharp point being perpendicular to the top surface of the can as said can opener begins to pierce a can.

References Cited in the file of this patent UNITED STATES PATENTS 111621695 De Fee Oct. 31, 1950 2,569,905 Schwark Oct. 2, 1951 2,621,402 Gutenkunst Dec. 16, 1952 2,829,432 Haslett Apr. 8, 1958 2,900,716 Frans Aug. 25, 1959 FOREIGN PATENTS 1,142,078 France Mar. 25, 1957 

